A standard convertible couch or chair has a seat part which can be pulled out and folded over to form a sleeping surface. To this end complicated linkages are provided that interconnect the various frames that support the mattress in the reclining position. The sleeping surface is normally formed by a mattress that is folded up when the various frames are all fitted together in the sitting position. The uppermost portion of the mattress may serve as a sitting surface in such a chair or couch, or separate cushions may rest thereon to form such a sitting surface.
In order to decrease the length of the mattress needed, it is known to mount the back cushion of such a convertible seating unit so that it can be swung back to form a continuation of the upper surface of the mattress in the sitting position of such a unit. This expedient normally requires that the convertible couch be kept well away from the wall against which it stands, or that it must be pulled away from such a wall before the back can be flopped down. Furthermore it is necessary for the person converting such a seating unit into a bed to lean over the opened mattress part to operate the mechanism that folds down the back, a procedure which is relatively difficult and, in fact, impossible for a small person.